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From: Dominik K. <dom...@gm...> - 2023-03-03 07:42:53
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Dear Allen, few hints for your questions: If you will need InGaP often and all the variation of the lattice parameter and other needed parameters (elasticity?) are known well enough, then I think it would make sense to create a class derived from the 'Alloy' or 'CubicAlloy' classes like SiGe and AlGaAs. Regarding the scan directions on top of the reciprocal space maps: have a look here: https://xrayutilities.sourceforge.io/examples.html#line-cuts-from-reciprocal-space-maps and in the example https://github.com/dkriegner/xrayutilities/blob/main/examples/xrayutilities_read_panalytical.py There such scan directions are shown on top of reciprocal space maps. These directions can be automatically generated by doing line cuts. cheers Dominik On Fri, Mar 3, 2023 at 5:56 AM Allen Hall <aj...@gm...> wrote: > Hi Dominik! > > Thanks so much for this discussion/information regarding the package! > This is great news! Yes, I had a feeling it was 2theta-omega, but wasn't > sure on this... and you are of course correct it really only makes sense > for epitaxial crystals to use radial scans (with the exception of the > omega-rocking curve). Coming from the machine side, I'm used to using the > machines only in angle space, not in Qspace - so it takes a bit of head > scratching here and there to mentally go back and forth... I'm still > learning from your examples here. > > A few q's... I need to make an InGaP for my current work, and I see the > example for InP in the docs. I have in the past imported CIF's for say > CuInSe2, and that worked out ok... but wasn't sure if I should ask about > making a class like AlGaAs... there are a number of mixtures that are > similar to the AlGaAs issue - are these difficult to create? I could stick > to a common star-file ICDD file example of InGaP, but I wasn't sure if that > was limiting for modelling purposes. [I'm hoping to start simple here so > probably thinking about a new class is a bad idea to start with.] > > Lastly- an idea that might be cute... I'm tempted to try and draw lines > ontop of the RSM diffraction spot presentation... one could probably show > what a 2-theta-omega or omega or theta scan looked like at specific angles > but represented in q-space as a line or even curved square for planar > detectors... would this be farily easy to plot directly onto the same > axes? I guess we'd have to generate the poins in q-space based on the scan > parameters and then add them to the plot... > > Thanks so much for the excellent package! I'm enjoying learning from the > examples and the mailing list here. Big cheers, > -Allen > > > Allen Hall > aj...@gm... > al...@al... > (old:ah...@il...) > > > On Sat, Feb 25, 2023 at 10:50 AM Dominik Kriegner < > dom...@gm...> wrote: > >> Dear Allen, >> >> the simpack_xrd_InAs_fitting of course models a radial 2theta-omega scan. >> The documentation examples ( >> https://xrayutilities.sourceforge.io/simulations.html) also clearly >> specify that all models are for crystal truncation rod analysis (and are >> mostly tested for the symmetric 2theta-omega case). A pure 2theta scan >> would make not so much sense for an epitaxial system. so pure 2Theta scans >> can actually (somewhat limited) in xrayutilities only be simulated for >> powder/textured samples. >> >> So actually all "XRD" simulation examples are basically what you look >> for. I think the example file simpack_xrd_SiGe_superlattice.py could be >> particularly interesting since it shows also how a slightly more complex >> layer structure can be built. >> >> hope this helps >> Dominik >> > |
